U.S. Pat. No. 6,319,283 relates to a tibial knee component with a mobile bearing. More particularly, this patent relates to an orthopaedic knee component for implanting within a proximal tibia. The orthopaedic knee component includes a tibial tray with a proximal tibial plateau and a projection extending generally orthogonal to the tibial plateau. The tibial tray also includes a distally extending stem. A bearing is coupled with the tibial plateau and has an articular bearing surface for engagement with a femoral component. The bearing is rotationally movable between a first rotational limit and a second rotational limit about an axis extending generally orthogonal to the tibial plateau. The bearing has a backing surface engaging the tibial plateau which is sized and shaped such that the backing surface is substantially entirely supported by the tibial plateau at any position during rotational movement between the first rotation limit and the second rotational limit.
U.S. Pat. No. 5,683,468 relates to a mobile bearing total joint replacement. More particularly, this patent relates to a prosthetic component provided for a condylar joint. The prosthetic component includes a platform having a bearing surface and a pair of side walls. The side walls include a pair of concave surfaces which face one another and define arcs of the same right circular cylinder. The prosthetic component also includes a plastic bearing having a bearing surface slidably engaged with the bearing surface of the platform. The bearing also includes thrust surfaces defining arcs of two right circular cylinders having radii less than the radius of the side wall surfaces of the platform. The thrust surfaces are spaced from one another to permit only limited sliding movement of the bearing in medial to lateral directions, but greater sliding movement in anterior to posterior directions.
U.S. Pat. No. 5,556,432 relates to an artificial joint. More particularly, this patent relates to an endoprothesis for the human knee joint, consisting of at least two joint parts moving with respect to each other, a joint head and a joint base, with toroidal joint surfaces, that have function surfaces with differing circular intersection contours in mutually perpendicular planes—a longitudinal plane and a transverse plane—whereby the curve ratios of the function surfaces are defined in each of the planes as either convex-convex, convex-concave, or concave-concave, and the joint geometry of the function areas to each other in each of the two planes is determined by a link chain with two link axes (dimeric link chain), which proceed through the rotation centers of the function areas with the radii of the attendant intersection contours, respectively.
U.S. Pat. No. 5,358,530 relates to a mobile bearing knee. More particularly, this patent relates to a prosthetic mobile bearing knee including a femoral implant having condyle sections attached to a femur and a tibial tray implant having a plateau attached to a tibia. The tibial tray implant has a pair of spaced apart, concavely curved plateau bearing surfaces for cooperation and sliding with convexly curved surfaces on a tibial bearing. The tibial tray plateau bearing surfaces are shaped to create a gradually increasing resistance to sliding and rotational movement of the tibial bearing. The tibial bearing that interfits between the femoral and tibial tray implants is constructed in one or two portions.
U.S. Pat. No. 4,224,696 relates to a prosthetic knee. More particularly, this patent relates to a prosthetic knee having as its component parts a femoral implant, a tibial implant, and a meniscal plate disposed between the implants. Knee flexion and extension is permitted by compoundly curved condyle surfaces of the femoral implant, which resemble corresponding surfaces of a natural knee, and correspondingly shaped convex bearing surfaces in the meniscal plate. All other motions of the prosthetic knee take place at the interface between the meniscal plate and tibial implant. This interface is defined by a continuous, concave, spherically shaped surface in the upwardly facing plateau of the tibial implant and a corresponding, continuous, convex spherical surface of the meniscal plate. The components are biased into mutual engagement along the cooperating concave and convex surfaces by the natural ligaments which surround the prosthetic knee. The continuous biased engagement of the cooperating convex and concave surfaces of the prosthetic knee assure its stability.
Among those benefits and improvements that have been disclosed, other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying figures. The figures constitute a part of this specification and include illustrative embodiments of the present invention and illustrate various objects and features thereof.